There is either a lot of trolling or willful ignorance happening in this thread. From wikipedia's entry for "intersex":
"In biological terms, sex may be determined by five factors present at birth:
the number and type of sex chromosomes
the type of gonads—ovaries or testicles;
the sex hormones;
the internal reproductive anatomy (such as the uterus in females); and
the external genitalia.
People whose five characteristics are not either all typically male or all typically female at birth are intersex.
Some intersex traits are not always visible at birth; some babies may be born with ambiguous genitals, while others may have ambiguous internal organs (testes and ovaries). Others will not become aware that they are intersex unless they receive genetic testing, because it does not manifest in their phenotype."
Translation: it's not as simple you want it be. For people calling intersex people "he", I ask this: do you consider someone with XY genes but with a vagina a man or woman? What about XX but with a penis? Yes, those are both real conditions.
What about someone where the genes (XX or XY) don't match the gonads (ovaries or testes) AND external genitalia (vagina or penis) is ambiguous? What do you call this person? What may happen is that the parents and/or doctors just have to make a choice about the external genitalia and decide their baby's gender then and there. "Just try to make this into a vagina, doc, and we'll raise her as a girl". Never mind that then the secondary sex characteristics that emerge at puberty might not match.
So you see, it's not simple. It is truly possible for someone to be neither he nor she as we traditionally define them. So then that person just has to choose a category and try to live their life. Makes sense to me in that case to use their chosen gender pronoun since there is no sex pronoun for people part make and part female.